Green Spring is a census-designated place (CDP) and railroad town in Hampshire County, West Virginia, United States. As of the 2010 census, its population was 218. Green Spring is located north of Springfield on Green Spring Road near the confluence of the North and South Branches of the Potomac River. Green Spring is also the location of the South Branch Valley Railroad's terminus with the old Baltimore & Ohio Railroad mainline. Green Spring is the site of a one-lane low-water toll bridge that connects Green Spring Road to Maryland Route 51 in Oldtown, Allegany County, Maryland. This bridge is one of only 17 privately owned toll bridges in the United States. The toll for the bridge is currently US$1.50.

Hampshire County is a county in the U.S. state of West Virginia. As of the 2020 census, the population was 23,093. Its county seat is Romney, West Virginia's oldest town (1762). The county was created by the Virginia General Assembly in 1754, from parts of Frederick and Augusta Counties (Virginia) and is the state's oldest county. The county lies in both West Virginia's Eastern Panhandle and Potomac Highlands regions.